Pre-1970 Produced Glulams

[SperlingPE]

I have an existing building using glulam beams for the roof structure. I need to verify engineering properties (Fb) of the existing glulams.

Does anyone know of a glulam inspector/expert or firm that does such inspections?

 

[JAE]

This firm provides wood members (glulam) in the midwest:

Leslie Sales

 

[RARWOOD]

When was your building built? And in what area of the country was it built?

 

[SperlingPE]

The building was built in the mid-1950's.
The building is located in plains states

 

[JAE]

Well, check out that link - I know the guy (have worked with him in the past) and he knows glue-lam pretty well.

 

[RARWOOD]

I would not have any information going back to the 1950's. You might contact Sentinel Structures in Peshtigo, WI. Sentinel was one of the first companies to produce glulam in the US. You could also contact Alamco in Albert Lea, MN.

 

[SperlingPE]

Contacted AITC.org. They put me in touch with Bruce Pooley a former employee of AITC and current timber design engineer. Bruce Pooley gave me information concerning grading of glulams for the 1950's and more information on the glulam combinations that I have. Long story short, he suggested a reduction in the original Fb value and some increases in other values. This would be a conservative approach. For possibly better numbers the outer lams could be evaluated according to current tension lam requirements.

 

[dik]

It is possible that the material is/was 1500f if beam construction. You also might check to see what adhesives were used. There was a brief period when the trend was that non-waterproof adhesives were used.

Dik

 

[ThePioneer]

Structural glued laminated timber has been made at Peshtigo, Wisconsin since 1934. This was the PIONEERING effort in North America. The firm has been known as Sentinel Structures, Inc. since 1972.

http://www.sentinelstructures.com

Water resistant casein adhesive was typically used in the glued laminated timber industry for all interior applications until the 1960s. Some firms still used it into the 1970s. Casein adhesive is easy to spot - it is white. the glue lines will be white. It is an excellent adhesive for interior applications. It is not waterproof.

Design values could be all over the board in the 1950s, depending upon what was specified. (same as today). In our 1957 brochure, typical design values listed for Southern Pine glued laminated timber were: Fb=2400psi; MOE=1,800,000psi; Ft parallel=2600psi; Fc parallel=2000psi; Fc perpendicular=385psi; Fv=200psi.

Hope this helps.

 

[dik]

Thanks, Pioneer... the 1500f was for sawn lumber and 24f (2400) was for glulam bending. Also 18c (1800) for compression elements.

Dik

 

[RARWOOD]

ThePioneer.

In your thread you referred to our 1957 brochure. Do you work for Sentinal Strutures? The SWC in my user name refers to Structural Wood Corporation in Vadinais Heights Minnesota.

 

[ThePioneer]

Hi. No, I do not work for Sentinal Strutures. I do however, work for Sentinel Structures, Inc. Ya, nit picking I know. But spelling is important to me!